The piece is ominous, and thorough. But it is missing one big component. If the threat is so huge, and so many people know about it (many in that region already do), why aren’t people doing more to prepare? Schulz says only that we suffer from

“…a kind of temporal parochialism — an ignorance of or an indifference to those planetary gears which turn more slowly than our own.”

“Where we stumble is in conjuring up grim futures in a way that helps to avert them.”

That throwaway explanation of why people don't worry enough is facile and disappointing. The lack of concern is a central part of why the region is so vulnerable and bears more attention in the story. The geological and other sciences Schulz reports on so well may be able to define the physical threat, but the sciences of risk perception psychology, which she does not address, tell us far more about how we are likely to respond to that information. If people are inadequately prepared for the quake she warns about, that lack of preparation will be responsible for a great deal of the death and destruction along with the shaking Earth itself.

We don’t worry as much about future risks as those that are more imminent.

Emotionally, probabilistic risk assessments — as in, the odds are 1 in X over the next X years — are abstract, not concrete. They don’t grab us viscerally.

We’re lousy about understanding probabilities in general.

We care more about risks that are salient; the real thing, not a news story about something that may happen in the future. An earthquake in the news, especially in our area, carries way more affective weight than the idea of one.

A risk that is natural, even The Big One, worries us less than one which is human-made. (After 9/11/2001, I spoke with a man from LA who moved to Palm Springs, smack dab on top of the San Andreas fault to avoid the human-made threat of terrorism.)

Optimism bias — "it won’t happen to me" — lets us play down all sorts of risks, in order to enjoy their benefits. Including the benefit of living in places we choose to live, even if they are prone to natural disasters. Or the benefit of not spending a bazillion dollars on preparation for a down-the-road risk, so we can spend that money on other more pressing needs and desires.

The study of risk perception by Paul Slovic and others has made clear that how risky something seems is a matter of how we feel about the facts, not the facts all by themselves. Our fears often don’t match the facts. That may seem irrational, but it is a built-in feature of human cognition.

Which means that just telling people a risk threatens them is not enough to get them to take that risk seriously. Schulz’s piece does a public service raising the alarm, but unless a threat actually feels alarming, many of us are unlikely to worry enough to take proper precautions. This is one half of what I call The Risk Perception Gap, the risks that arise when we worry about some things more than the evidence says we have to or less than the evidence says we should. Like that guy from LA moving onto one of the faults known to threaten California.

Just noting that gap between our fears and the facts, and dismissing what seems to be an irrational lack of concern, isn't enough. Explaining why the Risk Perception Gap occurs, and how an understanding of the psychology of risk perception can be used to reduce the gap, is as important to natural disaster stories as Schulz's explanation of plate tectonics and the Cascadia fault. If we understand why natural disasters don’t scare us as much as they should, we can devise policies, and more effective risk communications, that speak to the affective aspects of the threat ... to raise appropriate concern. That will support the investments and encourage the actions necessary to get people more prepared, for an earthquake in the Pacific Northwest or natural disasters anywhere.